1. Field of Invention
The present invention relates to a method for manufacturing a liquid crystal display panel and a structure thereof. More particularly, the present invention relates to a method for manufacturing an optical compensated bend nematic liquid crystal display panel and a structure thereof.
2. Description of Related Art
Liquid crystal display (LCD) has so many advantages, including high picture quality, small volume, light weight, low driving voltage and low power consumption, that LCDs are widely applied in electronic products such as medium or small-sized portable televisions, mobile phones, videos, notebooks, monitors for desktop computers and projection-type televisions. Therefore, as time goes by, LCDs gradually replace present cathode ray tube (CRT) monitors.
For competing with the CRT monitors, LCDs are nowadays developed towards wide viewing angle and quick response speed. The presently developed LCDs with this trend include TN+film, multi-domain vertical alignment (MVA), in-plane switch (IPS) and optically compensated bend (OCB) LCDs. As far as TN+film, multi-domain vertical alignment (MVA) and in-plane switch (IPS) LCDs are concerned, these LCDs all have the feature of wide viewing angle and can be normally manufactured. However, all these LCDs suffer from the problem of slow response speed. In contrast, as far as optically compensated bend (OCB) LCDs are concerned, it is deemed the main stream of future LCDs because which possesses both the advantages of wide viewing angle and quick response speed.
Reference is made to FIGS. 1A–1C, which are schematic, cross-sectional views of a conventional optically compensated bend (OCB) LCD illustrating how a conventional optically compensated bend (OCB) LCD work. In the conventional optically compensated bend (OCB) LCD, plural liquid crystal molecules 13 are disposed in a space between the thin film transistor array substrate 11 and the opposite substrate 12. There are two alignment layers (not shown on FIGS. 1A–1C) respectively formed on the opposite surfaces of the thin film transistor array substrate 11 and the opposite substrate 12 so that, for the liquid crystal molecules 131 and 132, there is a pre-tilt angle between the liquid crystal molecules 131 and 132 and the adjacent substrates 11 and 12. As shown in FIG. 1A, before the optically compensated bend (OCB) LCD works, the arrangements of the liquid crystal molecules 13 are in a splay state. Only after the arrangements of the liquid crystal molecules 13 are converted from the splay state to a bend state (as shown in FIG. 1B), the optically compensated bend (OCB) LCD can just be ready to work. That is, before the conventional optically compensated bend (OCB) LCD is ready to work, it takes time to warm up to convert the arrangements of the liquid crystal molecules 13 from the splay state to the bend state. Thereafter, as shown in FIG. 1C, by applying voltages on the thin film transistor array substrate 11 and the opposite substrate 12 to produce an electrical field therebetween, the liquid crystal molecules 13 starts to rotate to make the conventional optically compensated bend (OCB) LCD work.
Although the conventional optically compensated bend (OCB) LCD possesses both the advantages of wide viewing angle and quick response speed, it takes a lot of time, e.g. from several seconds to several minutes, to warm up LCD. Besides, the liquid crystal molecules in bend state are not thoroughly stable, the arrangements of the liquid crystal molecules are still easily affected by external causes, such as electrical field or temperature. Accordingly, there is a need for the conventional optically compensated bend (OCB) LCD to be improved.